Patterns in exercise behaviour across pregnancy: a retrospective cohort study of physically active individuals from pre-conception to postpartum

PURPOSE: The safe upper limits of weekly exercise participation during pregnancy, as well as the modifications active individuals make to their weekly exercise behaviours while pregnant, are unclear. This retrospective observational study aimed to determine how active individuals modify their training behaviours before, during, and after pregnancy. METHODS: We analysed data from 21 participants (aged 26-41 at the time of survey completion) who were physically active prior to their most recent pregnancy. Participants shared the exercise data recorded using a fitness application or monitoring device before, during, and after pregnancy. Participants also completed surveys about maternal and neonatal health outcomes. We used mixed-effects models to analyse weekly changes in participants' total exercise duration, session duration, exercise frequency, and aerobic exercise intensity and volume. RESULTS: ) during at least one week of pregnancy. However, weekly exercise duration progressively decreased throughout the antenatal period, and increased during the first 12 weeks postpartum. All infants were born within the normal birthweight range (2500 to 4500 g), and 14 were born at full term (early term n = 5, late preterm n = 2). CONCLUSION: Our findings highlight that active pregnant individuals exceed weekly exercise recommendations, yet adapt their training load throughout pregnancy. These findings emphasise the importance of considering physical activity recommendations as relative in nature, and interpreting them in the context of previous exercise behaviours. Exercise professionals should provide individualised support to active individuals in their pregnancy and postpartum journeys.